*Nepomuk::KFileMetaDataWidget for context menu of transfers, fixes setting Tags
*Nepomuk::TagWidget for setting tags of groups, these are stored as Nepomuk::Tag now, fixes setting Tags
*MassUpdateJob for setting properties and tags

Adds NepomukController for easy access of useful operations like adding Tags.
Adds an own thread for removing Nepomuk::Resources (in NepomukController) if the files they were associated with do not exist anymore, it speeds up removing Transfers in such cases.
Adds virtual QList<KUrl> Transfer::files() const, that returns all files of a transfer.

Removes btnepomukhandler, metanepomukhandler and all the custom widgets used for Nepomuk stuff.

svn path=/trunk/KDE/kdenetwork/kget/; revision=1173966